WASHINGTON DC (USA Today) -- President Obama took questions from reporters Wednesday in his first full-scale news conference since March.

Obama made his first comments on the widening scandal that led to the resignation of CIA Director David Petraeus, plus addressed upcoming negotiations with Congress on taxes and spending cuts.

He also forcefully beat back attacks on U.N. Ambassador Susan Rice coming from GOP Sens. John McCain of Arizona and Lindsey Graham of South Carolina for her comments following deadly violence in Libya. Obama said the senators are trying to "besmirch" her reputation.

"If Senator McCain and Senator Graham want to go after someone, they should go after me," Obama said.

Highlights from the news conference are below.

2:25 p.m. ET: That's a wrap, Obama says. But then a question is shouted out and Obama declines to answer it because it was yelled out.

2:22 p.m. ET: Last question is about Syria and whether the United States would arm Syrian rebels. Obama says he was one of the first leaders to say Bashar al-Asad should go. He says the United States is in close contact with Turkey and other countries. Obama said he was "encouraged" that the Syrian opposition formed an umbrella group. "We consider them a legitimate representation of the aspirations of the Syrian people," Obama said. But, he added, the the United States is "not prepared" to recognize the rebels as a "government in exile."

2:21 p.m. ET: Obama notes it might be easier to deal with the fiscal cliff than to find a bipartisan solution on climate change.

2:18 p.m. ET: "I am a firm believer that climate change is real," Obama says. He adds that he doesn't know what Republicans or Democrats are prepared to do to solve the issue, but acknowledges it would involve "making some tough political choices." He said he won't go for anything that would have a negative impact on jobs.

2:16 p.m. ET: Next question is about New York City Mayor Michael Bloomberg's endorsement and what the president plans to do about climate change. "We can't attribute any particular weather event to climate change. What we do know is the temperature around the globe is increasing," he said.

2:14 p.m. ET: Obama says he wants a diplomatic solution to Iran and vows the country will not get a nuclear weapon. "I will try to make a push int he coming months to see ... if we can get this thing resolved. I can't promise that Iran will walk through the door," he said. Obama vows not to be "constrained by diplomatic niceties and protocols."

2:12 p.m. ET: Back to the fiscal cliff. Obama says he can envision the moment (that he wants to avoid) if there is no agreement before tax cuts expire and spending cuts take effect. He calls again for certainty for middle class families.

2:11 p.m. ET: Obama shares a light moment with Christi Parsons of the Chicago Tribune, who covered his first race for the Illinois state senate.

2:08 p.m. ET: Obama says he has one mandate and that's to help the middle class. "I don't presume that because I won an election that everybody suddenly agrees with me on everything," he said. "On the other hand I didn't get re-elected just to bask in re-election. I got elected to do work on behalf of American families and small business all across the country."

2:05 p.m. ET: Obama says there is no debate there needs to be accountability after four Americans were killed at the U.S. consulate in Benghazi. And he warns senators McCain and Graham again: "When they go after the U.N. ambassador apparently because they think she's an easy target then they've got a problem with me." He said he's not yet determined whether she is the best person for the State Department job.

2:03 p.m. ET ABC's Jonathan Karl asks about Sen. John McCain's vow to block Susan Rice from the secretary of State job. Obama says Rice has done "exemplary" work and has been professional. "If Sen. McCain and Sen. Graham and others want to go after somebody they should go after me.

Obama says "for them to go after the UN ambassador ... and besmirch her reputation is outrageous."

2:02 p.m.ET: "I hope and intend to be an even better president" in a second term, Obama says.

2 p.m. ET: The question is about improving relationships with Congress. "I will examine ways that I can make sure to communicate my desire to work with everybody," Obama says, adding he will not compromise when it comes to helping the middle class. "All of us have responsibilities to see if there are things we can improve on." Obama says Americans don't want to see "a focus on the next election. ...I don't have another election."

1:58 p.m. ET: Is Obama going to sit down with Mitt Romney? Obama says nothing has been scheduled yet. "Everybody needs to catch their breath," he says, adding he hopes it occurs before the end of the year. Obama says there are "certain aspects" to Romney's career that could be helpful, such as his "terrific" job running the 2002 Winter Olympics in Salt Lake City. Obama says he's not "prejudging" what Romney wants to do, nor does he have a specific assignment for his rival.

1:56 p.m. ET: Obama says he doesn't want a "vague" solution when it comes to reducing the deficit. "The American people understood what they were getting when they gave me this incredible privilege of being in office for another four years," Obama says as he repeats his call for the wealthy to pay their fair share in taxes.

1:55 p.m. ET: Back to the fiscal cliff. Obama says the problems are "solvable" and that "fair minded people" can come to an agreement. "I don't expect Republicans to simply adopt my budget," he says.

1:54 p.m. ET: Obama says that had he been told sooner then reporters could have been asking him today why he interfered in an ongoing investigation.

1:52 p.m. ET: NBC News goes back to the question: Should the president have known about the Petraeus investigation sooner than he did? "I am withholding judgment with respect to how the entire process surrounding Genl. Petraeus came up," Obama answers. "I have a lot of confidence in the FBI and they have a difficult job."

1:50 p.m. ET: Obama says he wants to move on a comprehensive immigration bill soon after his inauguration. It will include border security measure and should contain serious penalties for companies that hire illegal immigrants. Obama says there should be a "pathway for legal status" for those who are already living in the United States, and that these illegal immigrants should potentially pay a fine. He also said he wants to put into law what he did administratively that allows thousands of young illegal immigrants to stay in the country.

1:48 p.m. ET: The topic now is immigration and what is his vision for a "broad" plan. Obama said it was "encouraging" to see a "significant" increase in Latino voter turnout last week. "You're starting to see a sense of empowerment and civic participation ... that will be good for the country," he said.

1:47 p.m. ET: More on the fiscal cliff. Obama says, "We've got a clear majority of the American people who recognize if we're going to be serious about deficit reduction we have to do it in a balanced way." He says he wants "a big deal" and a "comprehensive deal."

1:43 p.m. ET: Obama says the country cannot afford to extend the Bush-era tax cuts for the wealthy. "A deal that helps the economy, creates jobs, creates certainty" is what he's looking for. After that, he says, he wants a process to set up reform of the tax code and entitlements such as Social Security. "There's a package to be shaped and I'm confident that the ... goodwill of both parties can make that happen."

1:41 p.m. ET: Obama says he doesn't want to "meddle" in the Petraeus investigation and declines to specify if he should have been notified earlier.

1:40 p.m. ET: "General Petraeus had an extraordinary career. ... By his own assessment he did not meet the standards he felt were necessary as the director of the CIA. ... From my perspective, he has provided this country has provided extraordinary service. My hope right now is that he and his family are amble to move and that this ends up being a single side note on what has otherwise been an extraordinary career."

1:39 p.m. ET: First question from AP's Ben Feller on national security and the Petraeus scandal. "I have no evidence ... from what I have seen that classified information was disclosed that in any way ... would impact national security."

1:37 p.m. ET: Obama says, "We should not hold the middle class hostage while we debate tax cuts for the wealthy." He's urging a deal before the holidays.

1:36 p.m. ET: Obama says he's "open to compromise and open to new ideas." He's pleased that Republicans want to find new revenue. " He notes everyone's taxes will go up if he and Congress cannot reach a deal on tax and spending cuts.

1:35 p.m. ET: Obama opens with a statement about the importance of creating jobs and the need for bipartisanship as he and Congress try to avoid the fiscal cliff. "We face a very clear deadline that requires us to make some big decision on jobs, taxes and deficits," he said. "I believe that both parties can work together."